1. Field of the Invention
The invention relates to load cells and refers more specifically to a load cell for providing an electrical or mechanical indication of a force applied thereto, which load cell is adjustable both as to cell sensitivity and indicator calibration.
2. Description of the Prior Art
In the past, load cells have included strain gauges connected to register the deflection, elongation or contraction of load cell members having a force applied thereto and to provide an indication of the force in accordance therewith. Also, force rings having strain gauges or linear voltage differential transformers connected thereto or thereacross have been known which provide an indication of deformation of the ring under load. Also, load cells of the scale type, including spring means and/or lever arrangements, for indicating a force applied thereto are relatively common.
All of these prior devices have particular limitations which are undesirable in certain applications. Thus, strain gauges must be permanently secured to a deformable member and because of their nature are subject to damage due to mechanical shock, improper adhesion, and the like. Force rings are limited in their application and are substantially incapable of sensitivity calibration as are strain gauge structures. Mechanical springs and leverage systems are generally inaccurate, extremely sensitive to hard use and sometimes are particularly complicated.